1. Field of the Invention
The present invention relates to a side rail that is selectably movable from a first up position over center to a second down position.
2. Description of the Related Art
Bed side rails have existed for many years. In a basic form, a side rail is permanently fixed to the side of a bed frame. The side rail acts to alert the person that they are nearing the end of the sleep surface. Side rails are also useful as an assist device or grab bar for stability and for making adjustments in positioning. Of course, there have been many improvements over the years. Some examples include:
U.S. Pat. No. (hereafter, “USPN”) 3,585,659 to Burst et al. is titled Safety Side Guard for Hospital Beds. It describes a generally rectangular safety side guard pivotally mounted upon the mattress frame of a hospital bed and movable around the pivotal mountings from an elevated guarding position to a lowered inoperative position. Stops are provided to limit movement of the guard into the positions and latch means are provided to secure the guard in an elevated position.
U.S. Pat. No. 4,747,171 to Einsele et al. is titled Hospital Bed Rail Assembly. This patent shows a hospital bed having a storable safety rail. The bed includes a frame having a pair of laterally extending slide tubes mounted thereto. A pair of mounting shafts are positioned within the tubes and secure the safety rail to the frame. A stop member is positioned near the inner end of at least one of the tubes. The mounting shaft includes a projection which abuts the stop member when in a first rotational position, but is able to pass thereby when in a second rotational position. The stop member preferably includes an inclined surface opposing the inner end of the slide tube to urge the projection, and therefore the rail, outwardly as the mounting shafts rotate to move the rail to the raised position. A retraction spring is provided for urging the safety rail towards the bed frame while in the lowered position. The safety rail also includes a brake mechanism to resist the gravitational forces urging it downwardly from the raised position.
U.S. Pat. No. 6,389,622 to Her et al. is titled Hospital Bed. It describes a bed frame having a bed frame, a bed platform, a front plate, a distal plate, and two separate siderails at each side. The bed platform is structured by plurality of plates made by injecting plastics from a mold and serving to enhance the structure. The elevation angle of the bed platform can be adjusted by a driving device. Each of the siderails can be lifted or descended so that the patient can get on or off the bed conveniently. The outer side of each siderail is installed with at least one inner concave groove for fingers insertion when pull or push the siderails for safely purpose. Inner side of one siderail is installed with a motor controller to drive the driving device. The design will prevent the event of losing or destroying since it is fixed at a proper place. Besides, lower corners of the front and distal plates are installed with an impact-proof head to prevent the patient or others from being harmed by the corners. In particular, movable clamping pieces comprising a fixing seat, a pressing plate, a movable rear clamping plate, and a tightening block, are preset to the front plate and distal plate. With the special connection of the movable clamping pieces, the front plate and distal plate can be assembled or detached conveniently and easily.
U.S. Pat. No. 7,591,034 to Kramer et al. is titled Apparatus and Method for Closing Hospital Bed Gaps. It shows a patient support including a frame, a mattress supported by the frame, and a set of siderails configured to block egress of a patient from the patient support. The siderails are configured to reduce gaps defined between the siderails and the other components of the patient support.
While each of these examples show devices that may work well for their intended purposes, none show a biasing mechanism useful to bias the siderail towards either the up or down position.
Further, none teach that going over center can increase the horizontal movement of the side rail in proportion to a net change in vertical position.
Still further, none show the use of hard stops in the up position to provide a strong structure to prevent failure.
Still further, none show a release lever that acts in addition to a fixed stop in an up position.
Thus there exists a need for a side rail that solves these and other problems.